The fatty alcohol is an important intermediate of various chemical products/household goods, demand therefor is significantly increasing in recent years, and there are extensive studies on processes producing the same at low cost while maintaining its qualities. Generally, the fatty alcohol is produced in the presence of a hydrogenation catalyst by catalytically reducing a starting material such as naturally occurring fat and oil, a fatty acid or a fatty acid ester, with hydrogen to form a crude fatty alcohol and then refining this product by distillation.
Generally, distillation residues generated in this distillation step have been disposed of so far, or as shown in “Production of Fatty Alcohols from Fatty Acids” by Theodor Voeste, JAOCS, Vol. 61, No. 2 (February 1984), pp. 350–352, a part of the residues have been recovered and mixed with a starting fatty acid and returned to the hydrogenation step.
In the fatty alcohol produced from a fatty acid ester through catalytic reduction, there remain a small amount of the unreacted fatty acid ester, and such fatty acid ester has a vapor pressure near to that of the fatty alcohol and is thus hardly separated therefrom. For the purpose of decomposition and removal of such unreacted ester, the addition of an alkali component at the time of distillation is known (EP-A 0454720). For the purpose of reducing impurities including carbonyl compounds such as aldehydes, the addition of an alkali component such as sodium borohydride or an aqueous solution of sodium hydroxide is known.